Not sure my thread title makes much sense, but then again, if I new what the name of the feature is that I'm asking about, I could phrase it better. Here's what I'm curious about:

I don't yet own a DSLR (waiting to see if/when the 70D materializes). I currently use (and love) the Canon G12 for the photos I take. One thing that has been VERY helpful when I started using Manual Mode almost exclusively was that if I press the (*) button, it sets shutter and aperture to what it would be if in auto. I can then tweak it quickly from there using the manual dials.

This has been a great "crutch" for me as I develop my knowledge/skills. It's also really handy if the light suddenly changes (like going from shade to sunlight or front-lit to back-lit). I can just press the (*) button to get me close in an instant, rather than twirling the dials like crazy.

Is there a similar feature on Canon's DSLRs?

I've fiddled with my brother's T3i briefly, but when I press the same (*) button on his camera, it looks like it locks exposure or something...

If anyone has a quick answer on this, it'll save me a lot of reading various manuals for something I don't know the name of...

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I got started trying to figure this out, and the G12 manual says it's an AE Lock button. I guess I don't understand its function very well in Manual Mode.

In Manual Mode, it changes the shutter and aperture to a value that appears to be mostly correct for the situation, rather than just locking it. Each time I press the button, it changes the shutter and aperture again to what it thinks it should be, given the lighting.

In P Mode, it locks the exposure settings until the next shot is taken. Pressing the button again in different lighting does nothing -- it's locked until I take the shot, just like the manual describes.

When I tried this feature in Manual Mode on the T3i, it behaved more like how the AE Lock is described in the manual (and like what I experience in P Mode on the G12).

Can AE Lock on a DSLR function the way it does in Manual Mode on my G12, or do they all behave like when I'm in P Mode? What am I missing?

First, you need to define the DSLR model. There is a range of them with different capabilities and prices. Obviously, a D1 X has more capability than a beginner Rebel. P&S cameras do try to be more friendly to a inexperienced photographer, rather than just letting him set what he wants.Generally, manual mode is just that. It gives you manual control over the aperture, ISO, and shutter. Depending on the model, a pointer in the viewfinder and or top lcd will show you if your settings will over or unnderexpose the image. But, it will not set shutter or aperture for you. The 5D MK III and 1D X does let you set shutter and aperture in manual and the camera will set ISO or you can set it manually.

Thanks for the input. In terms of DSLR model, I'm just thinking Canon's current EOS models (i.e. do any of Canon's current DSLRs have a function that behaves like the AE Lock button does on the G12 in Manual Mode). All the manual descriptions of AE Lock (or YouTube videos) show what I experience using AE Lock in P Mode, but not what I experience in Manual Mode.

I understand that Manual Mode is just that, manual. The manual controls are what attracted me to the G12. When I first started using Manual Mode, I used the dials for shutter, aperture and ISO exclusively. I discovered the convenient functionality of the AE Lock button quite by accident.

What has me confused/curious is that the functionality of the AE Lock button in Manual Mode is quite different than functionality in P Mode, or on other DSLRs that I've fiddled around with.

Anyone have both a DSLR and the G12 that can compare it directly to see what I mean?

Here's what I do with my G12:

1. Set the Mode Dial to M.2. Point the camera toward my subject, and press the AE Lock button (*).3. The shutter and aperture automatically adjust to "optimal" settings.

I can repeat these steps as much as I want, whether or not I take a picture in between. Each time I press the AE Lock button, the shutter and aperture adjust to the circumstances. I still have full manual control via the dials at any time. The AE Lock button just gets me close really fast.

I see how this would be a feature to help a beginner, but I also see how this can be a time-saver for when lighting conditions change rapidly. Of course, being a somewhat of a beginner myself, that may be why it would seem useful to me but not to a pro...

If any of the EOS DSLRs have similar functionality in Manual Mode, it would make my transition a little easier.

Can't speak for the G12, but in M mode I don't want a button press to change my exposure settings. Also, in M mode with Auto ISO, the AE Lock button should (and does) lock the ISO for the shot. Even with manually set ISO, the AE Lock button allows me to see the exposure difference between two regions (on the 1D X, at least).

Good point about an unintentional bump of a button changing your exposure in Manual Mode. I can see how that might be more inconvenient than how I use it with the G12 is convenient. Still, if an equivalent feature exists on a DSLR (or can be set as a custom function), that would make it less intimidating to make the move to DSLR.

Then again, I was a bit intimidated by the G12's manual settings when I first got it. It helped push me to learn about the fundamentals of the camera. Either way, it looks like the G12 was a good choice to smooth the transition between point-and-shoot and DSLR...

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Slowpoke_Rodriguez

First Post. I'm pretty sure I know what you are talking about. I can only speak for the 5Dmk2, which is the only Canon DSLR I've ever used. That camera has no function similar to what you are speaking about. Neuro's answer does sort of the same thing. In P mode if you half-press the shutter it gives you a program line exposure. From there you can spin the wheel on the back of the camera to adjust the exposure in half or third stop increments depending on your setting. This is as close as it gets for 5Dmk2.

What you are talking about is what the green button does on Pentax DSLRs. In Manual mode, pressing the green button gives a program line exposure and from there the front and back control wheels will move the shutter and aperture from that position. It's handy. That, and in body shake reduction are the two features I miss from my days of shooting Pentax. There are many other nice features on the 5Dmk2, and I don't regret the system change.

Thanks for your replies. So if I understand correctly, I could do a half-press in P Mode and then use exposure compensation to fine-tune from there? That would be like choosing P Mode on my G12 and then using the EV dial, which I do use, occasionally.

Honestly, I think I just need to experiment with whatever becomes my first DSLR until I figure out how to use it quickly and effectively. Little features like that green button on the Pentax are handy, though. Some days I like experimenting and developing my skills with the camera, and other days I just want to forget about it and enjoy whatever it is I'm taking pictures of (usually my family).

Looking forward to the day when I have enough practice/experience to do both! Right now I feel like I have the "soul" of a photographer (composition, art, et cetera) but lack some of the technical knowledge and skills to execute on the vision reliably or to the best quality...

Thanks again! Now, if Canon will just announce their next APS-C bodies soon...

I haven't really shot pentax since something like 96-97, so i not sure what exactly your talking about, but i agree that "p" mode is probably what you are referring to. All these auto modes(anything other than B, and M) are the same thing. you get to choose 2 (including ISO) of the exposure settings and the camera decides the others. it's no big deal though, as if you are in av mode and are wanting a faster shutter, you just open the lens up a bit, then the computer/camera will increase the shutter speed to allow the same light level. You should really know that the biggest difference between these modes is how they handle flash photography. Exposure comp works on top of this stuff, but i rarely use exposure comp. To me, it's just not handy. if i take a shot,and find it underexposed, i just increase the light via fstop-iso-shutter speed. the thing with exposure compensation is that it's just using the meter, and if i was to simply reframe a scene just slightly different I might get a completely different exposure. if for some reason i was consistently getting exposure errors i would use it, but i don't have that happen to often. something you also might not know is that the camera's meter is always live, no matter what mode you're in. so you could have the camera in "m" mode and while looking through the finder, just turn start spinning the wheels until you've moved the little indicator to the (0) setting. of course you can't just do this without a bit of thought, as you might wind up trying to take photographs with 5 second exposures or something by accident, but the fact that the meter is always "live" is fantastic.

i'm not familiar with the G12 or the function that you are speaking of but i wanted to post because something just didn't seem right in your approach to learning manual mode.

pressing the * button on your G12 to see what settings the camera suggest while you are in manual mode is not a great way to learn how to shoot in full manual mode imo. the camera cannot make creative decisions....ever. it can only give a measurement of the amount of light in a scene (to varying degrees of accuracy at that).

i teach all my students that they need to understand the reciprocal relationship of aperture, shutterspeed, and ISO as it pertains to exposure as well as the inherent characteristics a photo will have when changing any of these three variables. use the cameras meter readings as a guide to tell you how much light is in the scene and then YOU tell the camera what settings you want to shoot at. letting the camera suggest settings is counterproductive to really learning how to shoot in manual mode.

i would suggest shooting in Tv (shutter priority) or Av (aperture priority) to help you build on your understanding of how different settings will affect the look (not exposure) of your images. these modes will allow you to focus on changing one variable at a time (either shutterspeed or aperture) and the camera will choose a compatible setting to zero out your meter reading. once you gain an understanding of when you want to adjust your shutter to get a certain look in your photo vs when you might want to change your aperture you can then jump all into manual mode and adjust both while keeping your exposure where you want it.

i should add that i think exposure is subjective as well...the camera cant tell you what a good exposure is. you tell the camera what the "right" exposure is for each scene.

i should add that i think exposure is subjective as well...the camera cant tell you what a good exposure is. you tell the camera what the "right" exposure is for each scene.

Sometimes, not even that. Although my 1D X autoexposure handles snow and bright yellow walls better than any other camera I've had, it still needs a tweak or two (but I only needed +1/3 EV when shooting mostly snow the other day, which is pretty darn close!).